BritBike Forum logo
BritBike Sponsor BritBike Sponsor
BritBike Sponsor BritBike Sponsor
BritBike Sponsor BritBike Sponsor
BritBike Sponsor BritBike Sponsor
The Bonneville Shop BritBike Sponsor
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum
| Spiders Cartoons, | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
ShoutChat Box
Buy BritBike staff a coffee
Buy BritBike's staff a coffeeStill here since 1996 serving BritBike enthusiasts..
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Member Spotlight
marinatlas
marinatlas
FRANCE- DINARD -BRITTANY
Posts: 163
Joined: September 2006
Show All Member Profiles 
Newest Members
Loop, Filthy pup, Kevin Victor, Soupdragon, Gabby
10738 Registered Users
Top Posters(30 Days)
franko 121
reverb 53
DavidP 51
Popular Topics(Views)
924,933 mail-order LSR
Forum Statistics
Forums34
Topics67,180
Posts673,252
Members10,738
Most Online14,755
May 5th, 2019
Who's Online Now
50 registered members (Allan Gill), 289 guests, and 851 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 2 of 2 1 2
Re: pre-monoblock 101 [Re: John Healy] #778418
07/11/19 10:00 pm
07/11/19 10:00 pm
Joined: Aug 2001
Posts: 2,580
Oztralia
R
Rohan Offline
BritBike Forum member
Rohan  Offline
BritBike Forum member
R

Joined: Aug 2001
Posts: 2,580
Oztralia
Originally Posted by John Healy
Rohan: It is in small writing easily overlooked at the bottom of the page.

It is also on a page that is not easily found by their search engine.


I think you have completely missed my point John,
given that I QUOTED that small text in a previous post !!

P.S. I don''t know how I posted something 3 times, now fixed.

PPS Why have we diverged into Monoblocs. ?
Fuel density could be the reason for those 3 notches, I'm not sure if replies are directed at this ??
Would alcohol fuel require a different float setting ?

Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America


Re: pre-monoblock 101 [Re: Richrd] #778450
07/12/19 9:35 am
07/12/19 9:35 am
Joined: May 2013
Posts: 5,606
West Yorkshire
Allan Gill Online happy

BritBike Forum member
Allan Gill  Online Happy

BritBike Forum member

Joined: May 2013
Posts: 5,606
West Yorkshire
Gasoline should be around the sg of 0.71 to 0.76, distilled water would have an sg of 1.0 (or 0.9982 to be more precice at 15*c), white spirit, diesel, and many solvents will have an sg of around 0.80 (methanol is 0.972) Thus us if you set your float height up using water or solvent, and use the liquid level to set the seat height, then soon as you switch to the lower density gasoline the float will sit more into the fuel thus the fuel level will be higher in the bowl, although not by a massive amout between methanol and gasoline.


Last edited by Allan Gill; 07/12/19 10:18 pm.

beerchug
Re: pre-monoblock 101 [Re: Richrd] #778463
07/12/19 1:07 pm
07/12/19 1:07 pm
Joined: Mar 2005
Posts: 10,232
Boston, Massachusetts
J
John Healy Offline
BritBike Forum member
John Healy  Offline
BritBike Forum member
J

Joined: Mar 2005
Posts: 10,232
Boston, Massachusetts
Yes, I changed the post.


Re: pre-monoblock 101 [Re: John Healy] #778503
07/12/19 10:23 pm
07/12/19 10:23 pm
Joined: May 2013
Posts: 5,606
West Yorkshire
Allan Gill Online happy

BritBike Forum member
Allan Gill  Online Happy

BritBike Forum member

Joined: May 2013
Posts: 5,606
West Yorkshire
Originally Posted by John Healy
Yes, I changed the post.


No worries, I was hoping that I'd over looked something. I've removed mine as it serves no purpose.


beerchug
Re: pre-monoblock 101 [Re: Richrd] #778531
07/13/19 6:11 am
07/13/19 6:11 am
Joined: Aug 2001
Posts: 2,580
Oztralia
R
Rohan Offline
BritBike Forum member
Rohan  Offline
BritBike Forum member
R

Joined: Aug 2001
Posts: 2,580
Oztralia
Another float needle with multiple notches.
(and imperfect focus...)
Although obviously not the same as previous.
I'm starting to wonder if this is an undocumented feature, rather than homemade modifications ?

[Linked Image]

Re: pre-monoblock 101 [Re: Richrd] #778686
07/15/19 3:17 am
07/15/19 3:17 am
Joined: Aug 2001
Posts: 2,580
Oztralia
R
Rohan Offline
BritBike Forum member
Rohan  Offline
BritBike Forum member
R

Joined: Aug 2001
Posts: 2,580
Oztralia
Something else I see which can vary is the different heights of collars(arrowed) under the mixing chamber.
This would rather alter the fuel height inside.
Anyone know how/why this may be, I'd think the carb on the right would be impossible to operate as is.
Would a different form of float bowl be required ? or ....

[Linked Image]

Re: pre-monoblock 101 [Re: Richrd] #778736
07/15/19 7:17 pm
07/15/19 7:17 pm
Joined: Aug 2001
Posts: 2,709
Springfield Nebraska
Richrd Online content OP
BritBike Forum member
Richrd  Online Content OP
BritBike Forum member

Joined: Aug 2001
Posts: 2,709
Springfield Nebraska
thanks for all this info.

the reason for the original post is that we are working on a rapide with new carbs and some problems. It ran great with Concentrics.

but with the new carbs there is a big stubble at 1/2 to 3/4 throttle, right where you'd expect the mains to be kicking in. Paul tried raising the needles but that makes it worse across the board.

and one carb does like to leak out the bottom.


Rich (last remaining member ThreeMustGetBeers)
"It's not always about going fast. Sometimes it's nice to slow down" (Wendy E.2016)

69 bonney
72 commando
75 commando interstate
06 Suzu..Suzu.. uh appliance
couple of beesas a ducati
and the Snake Bike
and a Honda?
Re: pre-monoblock 101 [Re: Richrd] #778738
07/15/19 8:09 pm
07/15/19 8:09 pm
Joined: May 2013
Posts: 5,606
West Yorkshire
Allan Gill Online happy

BritBike Forum member
Allan Gill  Online Happy

BritBike Forum member

Joined: May 2013
Posts: 5,606
West Yorkshire
That leak could be the problem. Or do you have the correct float bowls for the cylinder they are being fitted to?


beerchug
Re: pre-monoblock 101 [Re: Richrd] #778751
07/15/19 10:34 pm
07/15/19 10:34 pm
Joined: Nov 2011
Posts: 5,277
U.S.
Magnetoman Online content

BritBike Forum member
Magnetoman  Online Content

BritBike Forum member

Joined: Nov 2011
Posts: 5,277
U.S.
Originally Posted by Richrd
with the new carbs there is a big stubble at 1/2 to 3/4 throttle, right where you'd expect the mains to be kicking in. Paul tried raising the needles but that makes it worse across the board.

and one carb does like to leak out the bottom.
Based on too little information I'll go out on a limb and say your main jets are too large, causing the stumble because it is too rich, and raising the needle was the wrong thing to do since it only made it richer in the 1/2-3/4 range, which is before you'd expect the main jets to be kicking in. Along with this, either the float level of one carburetor is too high or, if the leak really is coming from the bottom and not just collecting there, the gasket at the bottom is leaking.

Page 2 of 2 1 2

Moderated by  Alan_nc 

Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.7.1